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Historical facts 1835 Berzelius J.J.: Theory of chemical catalyst 1860 Pasteur L.: yeast, catalyst boud to cells 1899 Buchner E.: Isolation of enzymes.

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Presentation on theme: "Historical facts 1835 Berzelius J.J.: Theory of chemical catalyst 1860 Pasteur L.: yeast, catalyst boud to cells 1899 Buchner E.: Isolation of enzymes."— Presentation transcript:

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2 Historical facts 1835 Berzelius J.J.: Theory of chemical catalyst 1860 Pasteur L.: yeast, catalyst boud to cells 1899 Buchner E.: Isolation of enzymes of alcoholic fermentation 1926 Summer B.J.: Preparation of plant urease in crystalline form Northrop: Isolation of p epsin, tr y psin and chy motr y psin in crystalline form The enzymes: proteins (99,9%)‏

3 Enzymes Biochemical, physiological role Regulation of the enzyme activity Therapy Their clinical role

4 Catalyst 7 Catalase 13Pt ( c olloid al ) ‏ 18 Without catalyst G o kcal/m ole H 2 O 2 decompositon

5 G & K Exergon: spont aneously, G 1 Endergon: G >0 K<1

6 Enzymes: Common in mode of action Enz yme : substrate binding side Active site Substrate

7 Enzyme activity: influence of temperature t o C Ac % Increase in temperature: increase of activity Increase in temperature: heat denaturation

8 Enzymes: pH optimum pH = 8 pH = 2pH = 6 Activity trypsinCholinesterasepepsinpapain

9 The lock and key ; theory of the induced fit +

10 Endopeptid ases

11 Exopeptid ases Aminopeptid ases C arboxipeptid ases

12 Proteolytic activation of zymogens Intestine Pancreas Trypsinogen Chymotrypsinogen  - Chymotrypsin Trypsin Enteropeptidase  - Chymotrypsin Trypsin inhibitor Inactive trypsine

13 1……………………………………………………………………..245 Chy motr y psinog e n 16…………………………………………..2451…………..15 Tr y psin - Chymotrypsin Chymotrypsin 16…………………… ………2451……….13 - Chymotrypsin

14 The Chymotrypsin hydrolysis peptide and ester bonds Hydrolysis of peptide bond Hydrolysis of ester bonds

15 Substrate specificity of Chymotrypsin Phe Typ Trp Met

16 Chymotrypsin reacts with DIPF at Ser 195 –OH CH 2 OH Ser 195 CH 2

17 Kinetics of chymotrypsin catalysis (measured by synthetic substrate)

18 time [milisecundum] A Burst phase Steady state condition Kinetics of chymotrypsin catalysis (measured by synthetic substrate)

19 Hydrolysis of peptide bonds EnzymeAcyl-enzyme Enzyme

20 Active site and its function of chymotrypsin

21 Hydrolysis of peptide bond – by chymotrypsin

22 Acyl – enzyme intermedier Tetrahedral intermedier Hydrolysis of peptide bond – by chymotrypsin

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24 Homolog enzymes Chymotrypsin – Phe, Tyr, Trp, Met Trypsin - Arg, Lys Elastase – short side chain residue i. e..: Ala, Ser Thrombin – Fibrinogen, V, VIII, PC Plasmin - Fibrin,

25 Substrate binding site of chymotrypsin, trypsin & elastase OO Asp 189 Val 216 Val 190 Chy motr y psin e Tr y psin e Elast ase

26 C y stein, aspartil and metalloprote ases : peptide cleavage Papain e – isolated form papaye Nu c leofil ic attack - peptide bond C atepsin s – immun systems C asp ases - apopt ose

27 Cistein, aspartil and metalloproteses: peptide bond cleavage Asp – proton ated Asp – deproton ated H 2 O Renin Pepsin

28 Cistein, aspartil and metalloprote ase : peptide cleavage Ba c teri a l termol ys in e C arbox y peptid ase A Zinc prote ases (m a trix metalloprotein ases MMP) MMP – tissue degrad ation and remodelling

29 Catalytical mechanism of acetylcholinesterase

30 Organic phosphate inhibitors of acetylcholine esterase Sarin – Tokyo-i tube Tabun Chemical weapon légzésbénulás Parathion – rovarirtó Rádioaktív DIFP egér izom diagfragma végkészülék: / mm 2 receptor

31 Physostigmine (Eserin) Physostigmine carbamoylates the Ser-OH of the acetylcholinesterase The rate of hydrolysis of the carbamoyl enzyme intermedier is low Trial by ordeal

32 Neostigmine Neostigmine carbamoylates the Ser-OH of acetylcholine esterase Inhibition of acetylcholine esterase [acetylcholin] enhancement; Intraocular pressure - decreased

33 A gyomor és hasnyálmirigy zimogénjei SzervZimogénAktív enzim GyomorPepszinogénPepszin HasnyálmirigyKimotripszinogénKimotripszin HasnyálmirigyTripszinogénTripszin HasnyálmirigyProkarboxipeptidázKarboxipeptidáz HasnyálmirigyProelasztázElasztáz

34 Enteropeptidáz Tripszinogén Tripszin ProelasztázProkarboxipeptidázElasztázKarboxipeptidáz Kimotripszinogén Prolipáz Kimotripszin Lipáz


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